Fragmentation of Water Molecule by Slow Multiply Charged Ions

Fragmentation of molecules subsequent to the interaction with ions has been studied intensively in the last decade, with the focus on relatively fast projectiles (the interaction time is 1-2 orders of magnitude smaller than the dissociation time). If the projectile is slow that the interaction time is comparable with the dissociation time, it strongly alters the angular and energy distribution of ionic fragment.

The energy and angular distribution of ionic fragments from water molecules formed upon impact of highly charged 1-220 keV Xeq+ ions (q=10, 15 and 22) was studied. These results are compared with our previous studies of water fragmentation induced by He1,2+, Ne(3-9)+ and Ar13+ ions [1-3]. A strong difference of the intensities and kinetic energy of ions scattered in forward and backward directions is observed as a function of the ion velocity. The data are interpreted by means of a classical trajectory simulation within the framework of a Coulomb Explosion.